Battery Capacity

Just like li-ion batteries can come in a variety of physical sizes, there is also a range of battery capacities available. A battery capacity, labeled in milliamp hours or mAh, clues us in to how much charge the battery can hold. What this means for you is the larger the capacity of the battery, the longer runtime you’ll get on a single charge.

Battery Voltage

Voltage lets you know the electric potential of the battery, or in simpler terms, how strong the electric current is when discharged from the battery. Most li-ion batteries have a low voltage between 3 and 3.7V.

Battery Output Current

While voltage tells us the strength of the battery output, we also need to know how much electrical current is flowing at a given time. For this we can look at a battery’s discharge rate which is measured in amps or A.

A standard, button-top 18650 battery will usually have a discharge rate around 5A (or often not list the discharge rate at all!). As advances in LED technology have demanded higher and higher outputs, nowadays you’ll see some flashlights like the EC23, MH23 and HC33 require a high discharge rate to enable the brightest modes. If this is the case for your flashlight, you’ll want to seek out batteries that meet the minimum discharge rate specified by the manufacturer.

Flat-top vs. Button-top

With a few exceptions, NITECORE flashlights require button-top batteries to function. Not only does this ensure a proper contact inside the flashlight, but the “button” is actually a small protective circuit that helps prevent short circuits and over discharging.

Specialty Batteries

You might see some NITECORE batteries labeled as HP or USB-rechargeable and wonder what the difference is or when you might need these batteries. Here’s a quick run down of some speciality li-ion batteries available and when they come in handy.

High performance

Some flashlights need batteries with a high discharge rate in order to reach the brightest outputs. You’ll find batteries with an “HP” designation after the numerical name will provide high drain outputs that are often required to get your flashlight to reach the full brightness potential.

One good reason not to shy away from High Performance batteries: they’re backwards compatible! If you have an older LED flashlight that runs on regular old 18650s, you can still use HP batteries without worrying about the higher discharge rate affecting your device. We frequently recommend these Nitecore batteries to anyone who currently owns an older model but thinks they might upgrade in the future to one of our high performance flashlights.

i Series battery

Latest technology advancement has led to the creation of the Nitecore i Series 21700 battery. These Nitecore batteries have an “i” designation on them. This battery has taken battery performance to the next level with its powerful output.

The 21700 i Series battery has a dual way output with positive and negative polarities at both ends and a high energy density of up to 240mWh/g. This enables it to have a highly efficient output by minimizing the loss of power due to internal resistance. The reduction of the internal resistance grants the battery to offer a direct energy conversion to power the device. This battery is ideal for high drain devices.

DW Series battery

The DW Series battery was designed specifically for the R40 V2 flashlight and can only work with this flashlight. Because this flashlight is mainly used as a work light it means it needs a powerful and long battery life, which is exactly what the DW series offers.

The NITECORE NL2150DW has an amazing 5000mAh capacity. This powerful battery has improved performance, and superior energy density compared to previous 18650 batteries. The DW Series battery design allows for the R40 V2 flashlight to charge wirelessly via two docks provided with the flashlight. The battery also features a built-in pressure relief valve, high temperature resistant design, and built-in safeguards to prevent surges. This protects you from overcharging, over-discharging, as well as short-circuits.

USB Rechargeable

One of the newest advances in li-ion batteries is the introduction of USB rechargeable batteries. That’s right, these cells come with a micro-USB or USB-C port built directly into the battery! These Nitecore batteries have an “R” on them.

If you’re looking to minimize your carry or want to supplement a flashlight that doesn’t have a built-in charging port, these Nitecore batteries are for you. Compatible with common USB power sources such as power banks, solar panels and laptops (and traditional chargers, too!), all you need to do is plug these batteries in to charge. An indicator light underneath the positive pole goes from red to green to indicate charging progress.

Low temperature

If you plan on using your flashlight in cold temperatures (think sub-zero), you might want to consider picking up Nitecore batteries designated for use in low temperatures. Designated as LT in their model names, these batteries are optimized for, you guessed it, low temps.

Traditionally, CR123A batteries were the preferred power source for anything cold weather due to their chemistry’s superior performance. Now, NITECORE makes the NL1829LTP low temp battery, NL1829LTHP low temp, high performance battery and NL1829RLTP USB rechargeable, low temp, high performance battery — all designed to perform in cold temperatures all the way down to -40 F.